The contract was hailed by Gov. Chris Christie and the nation’s top teacher’s union official as an example of adversaries joining forces to rebuild a struggling urban school district.

The contract made Newark the state’s first district to allow for teacher merit pay and peer reviews.

But the implementation of the contract, including a dispute over emphasizing teacher performance in determining layoffs, has devolved into a bitter fight between Superintendent Cami Anderson and teachers unions.

According to the district’s projections, about 30 percent of Newark’s 3,200 teachers need to be laid off over the next three years to close a projected $100 million budget gap, while some new teachers will need to be hired in hard-to-staff subjects.

A recent request by Anderson for a waiver that would allow her to circumvent state tenure rules and base layoffs on a teacher’s effectiveness rating along with years of service has provoked the ire of local teachers unions and American Federation of Teachers head Randi Weingarten.

Anderson argues that performance-based layoffs are the only way to ensure that the majority of those let go are among the lowest-performing teachers. Without considering performance, Anderson claims most layoffs would come from the pool of high performers.

“(Newark’s school district) must address its fiscal crisis while increasing teacher quality,” Anderson wrote in the waiver request. “The only way to do this is to be granted an equivalency to right size with quality alongside years of service in order to remain competitive and offer quality schooling options for all Newark families.”

The layoffs are part of her wider “One Newark Plan,” which calls for creating “100 excellent schools” by 2017 by transforming existing schools or creating new ones, expanding charter schools, downsizing the workforce in some areas and increasing it in others, and establishing districtwide frameworks for accountability and teacher and student evaluations.

The district has also been working to replace the traditional enrollment model in which students attend the public school closest to their home with universal enrollment, which allows families to use a central online gateway to research school options and submit an application with ranked preferences for both public and charter schools.

Anderson says the plan has been developed with extensive community and stakeholder input, and she cites the 10,000 families that have signed up under open enrollment as proof that parents want better schools for their kids.

But union officials, some state lawmakers and hundreds of angry parents have blasted Anderson’s waiver request as the latest example of her trying to implement changes with no community input while disregarding the contract she once endorsed.

They argue that recently revised state tenure law allows for performance-based teacher dismissals. The state Senate recently approved a resolution calling Anderson’s waiver request “an attempt to usurp the authority of the Legislature.”

Anderson and her team argue that the state tenure law process is costly and lengthy to arbitrate and cannot be executed fast enough to keep pace with the growing financial crisis in the district and its low-performing schools.

Christie recently reiterated his support for Anderson in his State of the State speech, crediting her with expanding early childhood enrollment and increasing graduation rates in Newark by 10 percent.

“Newark is leading the conversation in making sure every kid – those who are behind, those who are ahead and those who have special education needs – are lifted up,” Christie said. “Under Cami Anderson, every kid means every kid.”

Kimberly Baxter McLain, who heads the Foundation for Newark’s Future, which administers the Zuckerberg donation, said she’s satisfied with how the investment is going. About $80 million of the challenge grant has been invested so far — $48.5 million of it in the teacher contract, she said.